I woke up this morning and discovered I'd been sleeping with a dried furball on the top sheet! Obviously I hadn't noticed it and I have no idea how long it had been there 
We seem to be getting about one furball a week now - is there anything I can do to prevent them? Harry seems to be fine in himself and is eating and drinking as normal. The furballs seem to have increased since he we increased his wet food (he's on a mixture of Natures Menu 'normal', Country Hunter and James Wellbeloved dry food). He does like to have a very thorough wash after he's eaten wet food.
Thanks in advance for any tips!